<div>
  <a [routerLink]="['/']">Home</a>
  <p>
    <a [routerLink]="['/app/app1/home']" [routerLinkActive]="['active']" [routerLinkActiveOptions]="{exact: true}">APP 1</a>
  </p>
  <p>
    <a [routerLink]="['/app/app1/welcome']" [routerLinkActive]="['active']" [routerLinkActiveOptions]="{exact: true}">APP 1 Route 2</a>
  </p>
</div>
